# This workflow builds and pushes a Docker image to GitHub Container Registry (ghcr.io) on every push to main.
#
# The Docker meta step is required because GitHub repository names can contain uppercase letters, but Docker image tags must be lowercase.
# The docker/metadata-action@v5 normalizes the repository name to lowercase, ensuring the build and push steps use a valid image tag.
#
# Without this normalization, you may encounter errors like:
#   ERROR: failed to build: invalid tag "ghcr.io/jgsuess/FHIRFLARE-IG-Toolkit:latest": repository name must be lowercase
#   Error: Process completed with exit code 1.
#
# This workflow uses the IMAGE_NAME environment variable set by the Docker meta step to guarantee a valid, lowercase image name.

name: Build and Push Docker image

on:
  push:
    branches:
      - main

jobs:
  build-and-push:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout repository
        uses: actions/checkout@v4

      - name: Log in to GitHub Container Registry
        uses: docker/login-action@v3
        with:
          registry: ghcr.io
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}

      - name: Docker meta
        id: meta
        uses: docker/metadata-action@v5
        with:
          images: ghcr.io/${{ github.repository }}

      - name: Set normalized image name
        run: |
          if [[ "${{ github.ref_name }}" == "main" ]]; then
            echo "IMAGE_NAME=$(echo ${{ steps.meta.outputs.tags }} | sed 's/:main/:latest/')" >> $GITHUB_ENV
          else
            echo "IMAGE_NAME=${{ steps.meta.outputs.tags }}" >> $GITHUB_ENV
          fi

      - name: Build Docker image
        run: |
          docker build -t ${{ env.IMAGE_NAME }} .

      - name: Push Docker image
        run: |
          docker push ${{ env.IMAGE_NAME }}